The present invention relates to storage systems for storing data, in particular, a technique relating to methods for the data protection of handled data, the data sharing, the storage resource management, and the data handling.
At present, environment in which the information processing is performed has been changing drastically as a result of development of the Internet and Intranets, and expansion of such applications as data warehouse, electronic commerce, and information service, and this change has resulted in rapid increase in the amount of handled data.
For example, while the performance of CPUs has improved 100 times for the last five years, the input and output performance of disk drives has been held in about 10 times improvement. That is, the limit of the input and output performance compared with rapid increase in traffic has come to give rise to apprehensions. In addition, as applications such as enterprise resource planning (ERP), which processes a mass of data, and data warehouse have come to wide use, and information to be processed (documents, drawings, visual contents, etc.) has been diversified and communicated in Multimedia, demands of enterprises for a total disk capacity has increased two times a year on an average. Further, as storage capacities used in enterprises and others have increased and use of storages has been diversified, the running cost of storages has also increased. Furthermore, backbone data in main frames has been shared and utilized by individual departments.
Described below is the situation of the information processing environment resulting from increase in the amount of handled data by using FIG. 2. As shown in FIG. 2, relations between servers and storages are established in such a way that, for example, a main frame (MF) as a server for a large-scale computer, a UNIX server as a server for a medium-scale computer, and a PC server as a server for a small-scale computer are connected with their respective exclusive storages, for example, RAIDs (Redundant Arrays of Inexpensive Disks) and magnetic tapes (MTs), and client computers give instructions to their respective servers via a LAN and perform data processing by using an exclusive storage for the relevant server.
Recently, proposed was a Storage Area Network (SAN) environment in which a SAN is constructed between the various servers and storages described above, and individual servers are allowed to access to any of the storages. Here, the SAN means a network that connects multiple servers and multiple storages through fiber channels, and is used only for input to and output from storages, and a SAN realizes the sharing of various storages, high-speed data processing between servers and storages, and long distance connection.